Danah’s speech to the O’Reilly Emerging Technology Conference in March 2006, provides more basis for design of social network sites.  This is the conclusion, but the meaning is only understood by studying the paper. 

DESIGNING FOR GLOCALIZATION – To close, I want to offer some suggestions that will help you address issues that emerge when dealing with glocalized communities.

1. Empower users. Give them the ability to personalize and culturalize their spaces online. Let people create the contexts in which their expressions can occur so that they can help set and regulate the norms. This means everything from hackable HTML to open APIs to open source code that can spiral everywhere.
2. Provide the cultural environment where people can accidentally connect with strangers over meaningful things without being forced to face everyone on the system. Let users privatize or wall off access to only certain people for their own needs. Let users see the values of being public. Of course, balancing privacy needs with public possibilities with the lack of interest in dealing with the *whole* public is quite tricky. Anyone who can solve this design challenge with a robust system will win the hearts of users and investors.
3. Empower individual users to be cultural spokespeople. Give them the ability to modify the system for their communities and cultural needs. Again, this means openness of software or providing richer platforms to develop on top of.

Source: G/localization: When Global Information and Local Interaction Collide

One particularly insightful comment, is on the evolution of CraigsList, Flickr and Myspace. They have developed their own character, and that character outlived the very early days.  It continues even today, and new participants work with that and appreciate that. 

These three sites have many attributes in common. They all grew organically. They each have public personalities that early adopters feel connected to. The early adopters really felt as though they were participating in and creating an intimate community, even as the community grew to millions. Users are passionate

Bank sites have no character.  Well, unless you call monolithic, and stodgy a  character.  There is no personality.  And the $64K point.  Differentiation can only occur at the character level … trying to differentiate at the product and service level will always come back to price.

Brilliant stuff!